Conventionally, a combination weighing apparatus is used for combining articles with weights thereof measured so that the value of the combined weights is near or equal to a target value.
First, a weighing system for a conventional combination weighing apparatus will be described.
As shown in FIG. 9, a delivery conveyor 100 drops an article M to be weighed onto a distribution portion 2. Furthermore, after several or a multiple of articles M are collected, the articles M are put into a bag, and made into a product.
Supply troughs 3i each drop and provide the articles M on the distribution portion 2 to a plurality of pool hoppers 4i that are provided downstream of each of the supply troughs 3i. A gate 5i is provided on each of these pool hoppers 4i, and the articles M received, which are supplied from each of the supply troughs 3i, are temporarily stored and accumulated in these pool hoppers 4i. Weighing hoppers 6i are provided downstream of each of the pool hoppers 4i. Each of these weighing hoppers 6i is provided with a weighing head having a weight detector 7i for detecting the weight of articles M that are dropped into the weighing hopper 6i from the pool hopper 4i, and a gate 8i. A large collecting chute 9 is provided below the gates 8i, and the values of the weights of articles M detected at each of the weight detectors 7i are combined so that the weight of the articles M gathered together here has a value that is near or equal to a target value. The articles M are then dropped to a bag forming packaging machine (not shown) and the like on the downstream side.
In this manner, each of the hoppers is provided with articles that are dropped from above. Each hopper directly relates to the processing ability of the combination weighing apparatus, and there have been various proposals for the hoppers such as Japanese Unexamined Utility Model Publication No. 4-102292 (Abstract), Japanese Examined Utility Model Application Publication No. 5-11468 (FIG. 1), and Japanese Examined Utility Model Application Publication No. 5-28236 (FIGS. 2 and 5).